The present invention relates generally to supports for light fixtures. More particularly, the present invention is directed to a light stand having a fixture height adjustment mechanism.
It is often desirable to adjust the height of a light fixture to suit a particular application. For example, growers of plants often use artificial light to provide the plants with the light energy necessary for the plants to grow. Typically, the sources of artificial light are fluorescent fixtures that are positioned above the plants to radiate their light energy on plants located below the fixtures. To increase the flexibility of growing plants under artificial light, light stands have been developed to support one or more fluorescent light fixtures above one or more growing regions located below the fluorescent light fixture(s).
Light stands for growing plants under artificial light generally may be characterized as either fixed or adjustable. A conventional fixed light stand comprises two vertical supports spaced from one another and joined at their upper ends by a horizontal member. The lower end of each vertical support includes a base for stabilizing the light stand in a plane perpendicular to the horizontal member. A fluorescent light fixture is attached to the horizontal member at a fixed height above a growing region located below the light fixture. A drawback of fixed light stands is that they do not provide a user with the flexibility of adjusting the height of the light fixture above a growing region below the fixture.
A conventional adjustable light stand comprises two vertical support spaced from one another. An elongate fluorescent light fixture extends between the two vertical supports and is attached at each of its ends to a corresponding one of the vertical supports by a slidable connection that allows the light fixture to move vertically relative to each of the vertical supports. Each slidable connection includes a locking mechanism, such as a screw clamp, that allows each end of the light fixture to be secured to the corresponding vertical support at a desired height above a growing region located below the light fixture. Each vertical support includes a base for stabilizing the vertical support in a vertical plane perpendicular to the fluorescent light fixture.
A drawback of such an adjustable light stand is that it can be awkward and difficult for a sole user to adjust the height of the light fixture. For a sole user to adjust the height of the light fixture, the user usually adjusts the height at one end of the light fixture at a time. This is so because the distance between the vertical supports is typically on the order of 50-inches or more to accommodate a standard 48-inch fluorescent light fixture. Proceeding one end at a time, however, can cause the slidable connections to bind, particularly if the user attempts to raise one end of the light fixture to a height substantially greater than the other end.
In one aspect, the present invention is directed to a stand for an elongate light fixture having at least a first attachment element. The stand comprises at least a first generally vertical support having an upper end and a lower end spaced from the upper end, and a first generally horizontal member having a first end attached to the first vertical support adjacent the upper end, the horizontal member for suspending the light fixture therebelow. The stand further comprises at least a first height adjustment mechanism that includes a guide attached to said first horizontal member and having an arcuate surface a located above the light fixture when the light fixture is supported by the stand. The height adjustment mechanism further includes an elongate flexible member having an end, a first portion and a second portion spaced from the first portion. The end of the elongate flexible member is adapted for engaging the first attachment element of the light fixture and the first portion engages the arcuate surface of the guide. A securing device is attached to the vertical support and located between the upper and lower ends of the vertical support. The securing device is for releasably engaging the second portion of the flexible member.
In another aspect, the present invention is directed to a method of adjusting the height of a light fixture supported by a light stand. The light stand has at least a first substantially vertical support, a substantially horizontal member attached to the first vertical support, at least a first guide attached to the horizontal member, at least a first securing device attached to the first substantially vertical support and at least a first elongate flexible member attached to the light fixture at a first location and extending over and in contact with the first guide. The method includes adjusting a length of the first elongate flexible member played out from the first guide to position at least a first portion of the light fixture at a first desired height. The first elongate flexible member is then engaged with the first securing device to secure the first portion of the light fixture at the first desired height.